Would a shrimp or hermit kill two big whelks?

[ACBlinky]

I bought a pair of whelks a couple weeks ago (no clams, so no worries). They've been very well behaved, stirring the sand all day and chowing down on a silverside or other meaty fare every few days. My husband loved seeing these huge snails come up out of the sand like zombies at feeding time, and was the first to notice their disappearance.

The last time we saw them was just before I added a blenny and a BIG coral banded shrimp to the tank on Wednesday. The CBS went straight to the rock overhang and stayed there for nearly 24h, I really don't think she's the culprit, but then again, maybe she hunted them at night while I wasn't watching. The only other suspects are a 3" electric blue hermit and a large tiger pistol shrimp who have both been living peacefully with the whelks for quite some time. None of the fish could have killed them, I'm certain.

The last possibility is that they just died, but both at the same time? They were well fed, so I know they didn't starve, but maybe I have a hitchhiking predator I'm not aware of. Unless there's some aspect of whelk behaviour that would make them stay under the sand for days on end, they're definitely gone. They used to come running whenever they smelled food in the tank, and there have been quite a few feedings since they went AWOL; I haven't even seen their little snorkels, let alone either whelk come up out of the sand.

Any thoughts?

 

[Sk8r]

Nassarius variety?

They may hide fulltime. I have some large ones that very rarely surface.

Coral banded shrimp are aggressive, and have a bad rep for predation.

 

[DrBegalke]

If the CBS did kill them, wouldn't there be shells somewhere?

I think it's more likely they are hiding. Have you tried feeding the tank at night with lights off, and seeing if they appear then?

Good luck.